The blood pressure changes momentarily in accordance with changes in external and internal environments. Therefore, it is ideal to be able to continuously record heart beats one after another. Even though this continuous recording is impossible, however, it is also important to provide health care by measuring the change in blood pressure with time by periodically (intermittently) measuring the blood pressure in a day.
When periodically measuring the blood pressure by the conventional blood pressure measuring apparatus, the blood pressure is measured by winding a cuff on the brachium of a person to be measured. In this case, it is necessary to attach, to the body, a large cuff that covers the brachium and the main body of the blood pressure measuring apparatus connected to the cuff.
When periodically measuring the blood pressure by the blood pressure measuring apparatus, therefore, a person to be measured must live everyday life with the cuff being attached to the brachium and the main body of the blood pressure measuring apparatus connected to the cuff being attached to the body. This largely interferes with everyday life. There is also a burden on the person to be measured; he or she may feel pain because the brachium is pressed whenever the blood pressure is measured.
There is a method that takes this problem into account and measures the pulse wave by attaching a cuff to the earlobe and pressing it (patent reference 1). This method can make the cuff and main body smaller than a sphygmomanometer that measures the blood pressure by attaching a cuff to the brachium, and can also reduce the burden on a person to be measured. Patent reference 1: Japanese Patent Laid-Open No. 2005-6906